John Clinton Rodda, who has died after a long battle with cancer, was an athletics, boxing and sports-politics correspondent for the Guardian for more than 36 years. He won many awards for his ability to get a story, and spent two decades on the International Olympic Committee's press commission as well as serving on various sports bodies in Britain.

Rodda began his Olympic reporting career by the light of a Swan Vesta match, desperately trying to file his copy on the day's cycling events one night during the last London Games in 1948. He would spend the next half a century shedding a little light on Olympic sport, covering massacres at the 1968 and 1972 Games, reporting from Muhammad Ali's Rumble in the Jungle in 1974, and becoming the doyen of athletics writers.

Beckenham-born Rodda was evacuated during the Second World War, and attended seven different schools. In 1946, at the age of 15, he went straight into journalism, working at his local newspaper, the South London Press. With an Olympic venue, the Herne Hill Velodrome, on the newspaper's doorstep in 1948, Rodda got his dream assignment.

With no floodlights at the track in post-war London, Rodda was left in the dark when races overran the timetable. "I struggled with a box of matches to telephone my piece to Dixon's News Agency. I received 31s 8d per day: not bad for someone on £2 15s per week from a local paper."

Despite his best efforts, the teenaged Rodda "was severely rebuked over the phone by Arthur Dixon, the head of the agency, for not having carried a torch. It was something I would never bother with in the 50 years of journalism which lay ahead of me."

In 1952, Rodda married his first wife, Alice. During their 30-year marriage they had five children, which made his local paper's meagre wage insufficient. Rodda freelanced for the then Manchester Guardian, where he came under the influence of Larry Montague, the paper's athletics writer. When Montague retired, Rodda succeeded him. From the Rome Olympics in 1960 until Barcelona in 1992, Rodda never missed a summer Games.

Rodda's friendship with the Eton-educated Daily Mail journalist and Irish peer Michael Killanin, the IOC President from 1972-80, gave him tremendous access in sport's corridors of power and some influence, too. More than once, Rodda wrote a speech for a sports official that would change the way that sport was run.

But Rodda was, above all else, a tremendous reporter, who even put his own life at risk to get a story. Ahead of the 1968 Games in Mexico City, students, their lecturers and trade unionists gathered in the Square of the Three Cultures to protest at the cost of staging the Olympics in their dirt-poor country. Rodda joined some of their leaders on a balcony overlooking the square, and was forced to dive to the ground when armed police opened fire.

"The carnage went on for five hours," Rodda recalled nearly 40 years later, "before the Mexican secret police – with a gun in the right hand and a white glove on the other to mark their identity – sorted the foreigners from the Mexicans on our balcony and I was released from the horror."

It was Rodda's dogged work, spending time with doctors at the city's hospitals that proved that the Mexican junta's estimate of 35 dead after the shootings was a deliberate underestimate: Rodda's newspaper revealed to the world that at least 267 people were killed and 1,200 hurt.

Four years later, at the Munich Olympics, Rodda went to great lengths to gain access to the athletes' village after the Black September terrorist attack. Dressed in running kit, Rodda calculated that he might pass for an international athlete out for a training run. What he did not expect was to appear in a photograph in some English dailies the following morning, captioned as an athlete going out on a training run despite the emergency.

Rodda's knowledge of the sports he covered earned him respect: even Steve Ovett, the Olympic gold medallist who held most reporters in disdain, engaged Rodda to help him write his autobiography.

Ovett's former track rival, Sebastian Coe, led the tributes to Rodda. "The thing about John was that he absolutely loved athletics," said Lord Coe, now chairman of the 2012 London organising committee. "He had an absolute passion for it."

A year before he retired, Rodda and his second wife, Yveline, moved to Trull, near Taunton. He took to playing bowls and served on the Parish council until ill-health began to take its toll.